1. Field of the Invention
The present invention relates to a semiconductor device and, more particularly, it relates to a semiconductor device operating in a high frequency range exceeding several tens MHz.
2. Description of the Prior Art
A semiconductor device operating in a high frequency range is divided into a plurality of IC chips from a wafer after manufacturing, to be subjected to a high frequency characteristic test. Description is provided of a conventional method of measuring such high frequency characteristic with reference to FIGS. 1--3.
FIG. 1 is a plan view showing an example of a conventional high frequency IC chip, and FIG. 2 is a sectional view taken along the line 2--2 in FIG. 1.
An input electrode pad 2a and an output electrode pad 2b are formed on an IC chip 1 including circuits of various functions, to be in conduction with the respective circuits. A grounding metal member 4 is formed on the rear surface of the IC chip 1, to be in conduction with the front surface of the IC chip 1 through a viahole 3. As shown in FIG. 2, the input electrode pad 2a and output electrode pad 2b (not shown) are formed by microstriplines.
FIG. 3 is a plan view showing the device of FIG. 1 in a state of measuring the high frequency characteristic of the IC chip 1 thus formed.
In general, a plurality of such IC chips 1 are independently received in a chip carrier 6 to be in conduction with the exterior through a jig 5, which is adapted to measure the high frequency characteristic of the IC chips 1. Several hours are required to prepare for such measurement since the plurality of IC chips 1 are respectively obtained from the wafer and the chip carrier 6 is prepared in response to the chip size for receiving the IC chips 1, to be set in the measuring jig 5. Further, accuracy in measurement is reduced through parasitic capacitance of the jig 5 itself and resonance by the jig 5.
On the other hand, there has been developed a high frequency wafer probe, which can measure the high frequency characteristic through contact with a single surface of the measured object.
Such a probe is disclosed in "Precise MMIC Parameters Yielded by 18.about.GHz Wafer Probe", by K. R. Greason et al., Microwave System News, issued on May 1983, with reference to a basic method of microwave on-wafer probing.
Such a probe is also disclosed in "Microwave Wafer Probing Achieves On-Wafer Measurements Through 18 GHz", by D. E. Carlton et al., Microwave System News, issued on May, 1985, with reference to a calibration method in microwave on-wafer probing (particularly loss correction, crosstalk correction, etc., in a two-port device).
However, it is difficult to achieve on-wafer measurement of a semiconductor device through such a probe.
Since the surface of an IC chip provided with input and output electrode pads is entirely covered by a nitride film except for the parts of the input and output electrode pads, grounding lines must be extracted from a grounding metal member provided on the rear surface of the IC chip. However, measurement through the probe is performed by placing the IC chip on a stage, and hence it is difficult to bring the needle of the probe into contact with the rear surface of the IC chip.